From: Stanislav Fomichev sdf@google.com
[ Upstream commit 4af396ae4836c4ecab61e975b8e61270c551894d ]
When returning BPF_STACK_BUILD_ID_IP from stack_map_get_build_id_offset, make sure that build_id field is empty. Since we are using percpu free list, there is a possibility that we might reuse some previous bpf_stack_build_id with non-zero build_id.
Fixes: 615755a77b24 ("bpf: extend stackmap to save binary_build_id+offset instead of address") Acked-by: Song Liu songliubraving@fb.com Signed-off-by: Stanislav Fomichev sdf@google.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/bpf/stackmap.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 98ad9dc3587a..6a32933cae4f 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -314,6 +314,7 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, for (i = 0; i < trace_nr; i++) { id_offs[i].status = BPF_STACK_BUILD_ID_IP; id_offs[i].ip = ips[i]; + memset(id_offs[i].build_id, 0, BPF_BUILD_ID_SIZE); } return; } @@ -324,6 +325,7 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, /* per entry fall back to ips */ id_offs[i].status = BPF_STACK_BUILD_ID_IP; id_offs[i].ip = ips[i]; + memset(id_offs[i].build_id, 0, BPF_BUILD_ID_SIZE); continue; } id_offs[i].offset = (vma->vm_pgoff << PAGE_SHIFT) + ips[i]